Telegraph system



April 14, 1925. 1,533,117?

TELEGRAPH SYSTEM Filed Oct. 8, 1919 2 Sheets-Sheet 1 AndrewflDo/w/ W Patented Apr. 14, 1925.

' UNITED STATES PATENT OFF-ICE;

A NDREW D. DOWD, O'F HOBOKEN, NEW JERSEY, ASSIGNOB '10 WESTERN ELECTRIC OOHPANY, INCORPORATED; NEW YORK, N. Y., A CORPORATION OF NEW YORK.

'rnnnennrn SYSTEM.

Application filed October a, 1919. Serial in). 329,195.

To all-whom it may. concern:

Be it known that I, citizen of the United States, residin at Hoboken, in the county of Hudson, tate' of New Jersey, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, con- 'cise, andexactxdescription.

This invention relates toprinting teleg-. raphy andparticularly to multiplex printin telegraph systems of the start-stop distri utor type. I

The principal objects of thisinvent-ion are to provide a flexible system of communication between any number of stations,-one

which requires a minimum amount of main- 7 tenance and one which may readilybe applied to existing circuits andbe suitable for tions without employing complicate apparatus.

all classes of service.

A further object is the provision of means whereby two or more messages may be transmitted simultaneouslyfro'nr a'single station and recorded at one or morereceivin stad expensive synchronizing or speed-correcting By means of this invention any number of stations may be interconnected and any station may serve as. a transmittmg station,

while any or all of the remaining stations may serve as receivlng statlons. .1 For theaccomplishm'ent'of the above objects the invention contemplates the employment of a plurality of current control means co-operating with a distributor to form units of current impulses for the line. The current control means may com rise an automatic tape transmitter or a direct keyboard transmitter, either of which may cooperate with the sending'distributor to form characteristicgroups of current permutations;

A receivingdistributor is also provided at each receiving station -Y which op- I erates ilrisochronis'm with the sending distributor and cooperates with 'an electro-- mechanism. to distribute the eifects of the line current impulse to a suitable selecting mechanism; Applicant provides distributors with independent brushes for sending and-receiving, each brush being stopped auton t'e'ally, once perrevolution, thereby insuring restoration to synchronism at regular ntervals. Appli'cants system is especially adapted to operate on circuits including several stations and it permits a 1 greater variation in the speed of the dis- ANDREw D. Down, a

tributorsthan is permissible on multiplex circuits where a high degree of unison is re uired between distributors, consequently it 1s less dilficult and less expensive tomain description and claims and will be more '-readily understood by reference to the accompanying drawings wherein Fig. 1 represent? one specific. embodiment of the invention" in which five signaling units are required for the transmission of each character and two additional im ulses, one for starting the distributor, an stoppin or arresting the distributor; and Fig. 2 s ows a modification of Fig. 1 wherein only one additional segment, instead of two, is required for releasing and arresting the distributor.

The system of this invention is here shown adapted for use with a code composed of units of positive and negative current impulses, but obviously other codes may be used without departing from the hat of the invention. he system prefera 1y employs a metallic line conductor with the usual ground return and with polar duplex equipment at each station. Each of the accompanying drawings discloses a transmittin and receiving arrangement such as may e employed at a single station. It is readily ap arent that any number of stations similar y equipped may be interconnected and one station may be sending and all others receiving, or any two stations may'transmit and receive simultaneously.

In the accompanying drawings A and B are two distributor faces, preferably parallel to each other, each face consisting of a plurality of segmented and continuous rings. The distributor brush arms and 110 are frictionally mounted .on a constantly rotating shaft which may be driven by any suitable means, for example a motor." Each arm carries a pair of brushes which are adapted to sweep over its respective distributor face and interconnect the segmented'and contin* uous rings when the brush arm-is released, as will be hereinafter explained.

At each station there is rovided a plurality of transmitters 11 w ich control the selectively operable contacts 12, 13, 14, 15 and the other 'for 16. These contacts are permanently connected to 'corres' ending distributor segments and are adapte to be selectively operated to pick up positive and negative current from the'grounded battery 17. The-transmitting mechanism 11 may consist of automatic tape employed to operate any Suitable recording mechanism; for example they may be employedto operate selecting discs or permu- The key or switch 20 is now closed to tation bars of a receiving printer to effect the selection of a desired character. The actual printing of a character maybe efi'ected by a printing magnet (not shown), connected to a local segment 118 by means of conductor 119;

It will be understood that all distributors are adjusted to rotate approximately at the same speed and the receiving distributors are each controlled fromthe transmitting station.

' A better understandingof the system can be obtained from a description of the selection-of a particular character and the various operations which take place in transmitting and recording the impulses essen tial for the selection of a particular character. Let it, be assumed for example, that the character B is to be transmitted by the transmitter 11 and that the combination of cunrent impulses required is positive, negative, negative, positive, positive. Now if theselectively operable contacts-12 to 16 inclusive are actuated (by either an automatic tape control transmitter or a keyboard transmitter), the selectively operable contacts will be arranged to connect positive and negative batteries to the respective distributor segments 22, 23, 24, 25 and 26.

initiate the operation of the sending distributor by establishing an energizing circuit through the release magnet 21 from grounded battery 27, switch 20, release mag net 21, local segment 28,. distributor brush 29, local ring 30, to ground. Magpet 21,

upon being energized withdraws olding pawl 31 from engagement with the brush arm 10, thereby permitting the brush arm to rotate due to. its frictional engagement with a constantly rotating driving shaft. It will be noted from examination of distributor A, F ig. 1, that when the brush arm is at rest, positive battery is connected to the line circuit L through distributor segment 32, brush 33, ring 34, to the apex of the windings of polar relay 35, where the current divides and flows over the line L and artificial line AL. The instant, however, thesendingdistributor brush 33 passes from segment 32 and on to segment 36, a reversal of current is sent to the line from battery 17, segment 36, brush 33, ring 34. This reversal of current is provided for the purpose of initiatingthe operation'of the distributors B, at the receiving stations which will be efl'ected by the actuation of the receiving relays 35 whereby a circuit will be completed through each receiving start magnet 121 from grounded battery 37, tongue 38 ofrelay 35, conductor 39, receiving distributor ring 134, brush 133, seg

ment 136, through receiving startmagnet 121 to ground. The magnet121 on being energized, withdraws its holding pawl 131 from engagement with the brush arm 110.

The transmitting and receiving distributor brush arms have now been released-and sincefthey are adjusted to "rotate at substantially the same speed the distributor brush 33 will pass over sendin segments 22, 23, 24, 25 and 26, sequentiall thereby connecting those segments with the distrib- 'utor ring 34 while. during corresponding periods of time the distributor brush.133 willpass over receiving segments 122, 123, 124, 125, and 126, respectively, thereby connecting these segments wit-h the receiving distributor ring 134'. Theref0re, the instant distributor brush 33 engages segment '22, a circuit is completed from grounded battery 17 transmitter contact 12, segment 22, brush 33, ring 34, over the line circuit -L and through relay 35, at the receiving 'station. If (the impulse transmitted is a marking impulse the receiving relay 35 will be actuated to complete a circuit from grounded battery 37, relay tongue 38 con.- ductor 39, receiving ring 134, brush 133, segment 122, through the Winding of selecting magnet 112- to ground. Thus it will be seen that as the receiving distributor brush 133 passes over the receiving segments 122 to 126inclusive, the selecting magnets 112v to 116 inclusive of the selecting mechanism 111 will be actuated in various combinations depending upon the character of the impulses sent out from the transmitting station.

Referring to the equipment at the sending station, there is provided in connection with the transmitter 11 a magnet 40 which, for automatic tape transmission, may be utilized for the purpose of advancing the tape after the transmission of each group of character .impulses. This magnet is shown-under the control of the distributor and may be actuated at any-time after a group of impulses has been transmit-ted and is available for operating the transmitter magnet of each transmitter and permitting the contacts to settle before another group of impulses needs be transmitted.

with one less segment and associated therewith are-means for insuring a reversal of line currentso that the receiving dlstrlbutors may beset in operation at any time ref gardless of the character of the last transmitted impulse of a particular character.

Thev transmitters shown in "Fig. 2' and also the distributor releasing mechanism and duplex equipment is similar in a'll're'spects to that shoyg inoFig. 1, therefore no further description of this part of the system is deemed essential. In Fig. 2 the distribu'-- tor brush 33 normally stands at rest on distributor segment thereby maintaining the line circuit closed from grounded battery 17, transmitterjfcontact' 16, control relay 52, segment '50, brush 33, distributor ring 34, to the 'line L. As will be noted from the drawing the 'character'of the current applied to, the line when the, distribuse'quently the tongue 53 of control relay 52 if positive batte tor is at rest will-depend upon whether the transmitter contact 16 is actuated or unactuated, that is whether it is in engagement with its upper or lower contact. The character' dtlfcurrent connected to segment 51 is also dependent upon the position of the 11% tongue of control relay52. If the translower contact, the positivepole of battery mitter' contact lfi'is' in engagementwith its 17 will be connected to the line L, and conconnecting the negative pole of batto. the ad acent segment 51, so that is connected to the line circuit L when t e distributor brush rests on segment 50, current of opposite potential willbe applied to the-line L the instant the thereb tery 1 brush arin'is" released and the. brush engages segment 51 thereby sending out a reversal of line current to initiate the operation of the receiving. distributor. Referring. to-the receiving distributor Fig. 2,-

if it is assumed that the last impulse transmitted is of the character shown connected.

to transmitter contact 16, then the relay.

tongue 153 of control relay 152 will be in the position indicated in the drawing; con sequent-1y the start magnet 121 will remain I inert until the sending distributor brush 33 has assed from segment 50 on to segment 51.t1ereby sending out a reversal of current to complete an energizing circuit for the start magnet: 121' from rounded bat-l tery 37, relay tongue .38, con uctor 3 9,'dis- .tributor ring 134, brush .133, segment 136,

release magnet 121, tongue 153 of control relay 152 to ground. It is i material whether positive or negative current is applied to the line circuit L while'the sending brush 33 rests on segment 50, but it is important that the condition of the line or the .character of current on the line when the distributor brush 33 connects segment 51 this arrangement is to insure that the condition of the line circuit will be altered the instant the sending distributor is set in motion in order that the. receiving distributor may be released immediately to distribute the impulses from the transmitting static-ill The control relay 152 is provided with two windings, the circuit of one'winding being controlledfrom a local segment 154 on the distributor B, the other winding having one terminal connected to the receiving segment 126 and controlled by the last signaling im-' pulse'of a character group. The relay 152 is arranged so that its tongue 153 will be in a position corresponding to the tongue 38 of -relay 35 at the completion of each revolu-' receiving relay is'actuated to move its contact tongue from one contact to the other.

" 1 While in the accompanying. drawings only two transmitting and two receiving instruments are illustrated at eachstation, it

will be understood that any number of transmitters may operate to line L through the distributor A and a corresponding number-or receiving instruments may be' associated with the distributor B.

or more channels of'communication are required and where it is difiicult to obtain experienced help for maintenance purposes. It is far less expensive than the well-known multiplex synchronous equipment and is no less satisfactory.

, While the accompanying drawings show the preierred form of applicants invention, many changes and modifications may be made therein without departing from the "spirit of the invention.

segments upon the operation of said circuit This system is suitable for use where two controllers, a receiving rotary distributor having a plurality of groupsof segments, printing telegraph apparatus comprising a plurality of groups of selectin elements, means individual to each or said groups of segmentson said receiving distributor an'd responsive to the selecting impulses transmitted through the voperation of said cirgi itc controllers, as distributed by said receiving distributor, and distributor controlling means associated with each of said distributor's-.for periodically stopping and starting them, they distributor-controlling means in:

dividual to the receiving distributorv being controlled by impulses received from said transmitting distributor, the distributor COD.

trolling'means individual to said transmit- 'tin distributor being controlled independent y of said receivingdistributor.

2, A printing telegraph system comprising a transmittingrotar distributor, aplu ra ity of groups of con uctive segments on nalingimpulse upon each of said segments upon the 7 operation of said circuit controllers,- a receiving rotary. distributor having a plurality of groups of segments, printin telegraph apparatus comprising a plura ity of groups of selecting elements, means 7 individual to each of said groups of segments on said receiving distributor and responsive to the selectingimpulses transmitted through the'operati'on of said cir- "cuit controllers as distributed by; said receiving distributor, means 'for periodically stopping both of said distributors, means ining a transmitting rotar distributor,- a plu eluding an additional segment common to said roups of segments on said transmitting rality of groups of con uctive segments on, said distributor, a plurality-of groups of cir-' distributor and operative in anintervalbetween the transmission of groups of signaling impulses, for causing t e transmitting distributor, and-thereafter the release of said receiving distributor after a period of time less than that required for the transmission of-a single'group of signal ing impulses.

.3. 'A printing telegraphsystem-comprising'a transmitting rotar distributor, a plu cuit controllers, one controller individual to each se ment, means for impressing a'signaling impulse u on each of said segments upon theoperation of said circuit controllers, areceiving rotary distributorhav-f ing a plurality of groups of segments, printin telegraph apparatus comprising aplura ity of roups of selecting-elements, means individua to each of said groups of segments on said receiving distributor and respons-ive to the selecting impulses transmitted through the .o eration of said cir-.

cuit controllers as istributed by said receiving distributor, means for periodical- 1y stopping both of said distributors, means including a single additional segment com mon to said rou s of segments on said transmitting istri utor, and operative in an interval between the transmission of groups of signaling impulses for-'"causing a transmitting rotary release of said distributor,

tor, and thereafter the release of said receiving distributor after aperiod of time less than that required for the transmission of a single group of sign-a1 impulses.

4. A' printingtelegraph system comprisdistributor, a plurality ofgroups ofcon uctive segments on said distributor, a plurality of groups of circuit controllers, one controller individual to each segment, means for impressing a signaling impulse upon each of said segments upon the operation of said circuit controllers, a receiving rotary distributor having a-plurality of groups of segments,

printing telegraph apparatus comprising a plurality of groups of selecting elements,

means individual to each of said groups of segments on saidreceiving distributor and responsive tothe selecting impulses transmitted through the operation of said circuit controllers as distributed by said receiving distributor, and distributor controlling means associated with each of said distributors, for periodically stop ing and starting. them, one of said. distri utor controlling means being operated by impulses received from. the other of said distributors, and the ,btheI of said distributors being operated in rality of groups of con uctive segments on said distributor, 'a plurality of groups of circuit controllers, one controller individual Ito each segment, means for impressing a signaling impulse upon each of said segments upon the operation of said circuit controllers, a receiving rota'ry distributor having a plurality of groups of segments, print- 1 ing -te egraphapparatus comprising a plurality of groupsof selecting elements, means individual to each'of said groups of seg- Y ments on said receiving distributor a-nd'rev sponsive to the selecting impulses trans- 0 mitted through the operation of said circuit controllers as distributed by said receiving and" distributor..- Controlling means associated with each. of said distributorsfor periodically stoppin and starting them, the distributor -'control ing means individual to said transmitting distributor being controlled locally and periodically after the transmission of an invariable number of groups of signaling impulses in accordance with the previous setting of said circuit controllers.

6. A printingtelegraphsystem comprising a transmitting rotary distributor hav ing a plurality of conductive segments, said segments being concentrically arranged, a brush arm for successively engaging said segments, means for periodically stopping and starting said brush-arm, a plurality of automatic transmitters corresponding in 1,

number to the groups of said segments a plurality of circuit controllers for each of I said transmitters, one individual to each of said segments, means for impressing a signaling impulse upon each of said segments upon the operation of said circuit controllers, and means individual to each of said transmitters responsive during the period of transmission of signaling impulses by one of said transmitters for producing a 1 change in the circuit relationship of said circuit controllers individual to the other of said transmitters.

In witness whereof, I hereunto subscribe my name this 3rd day of October A. 1)., 15 1919.

ANDREW D. DOWD. 

